Shuttle actuating mechanism



Jan. 9, 1951 M. L. HICKS SHUTTLE ACTUATING MECHANISM 4 Sheets-Sheet 1Filed NOV. 23, 1948 lllllllllllllllllllllllllll lllllll INVENTOR. MARVINL. flicks 1951 M. L. HICKS 2,537,895

SHUTTLE ACTUATING MECHANISM Filed Nov. 25, 1948 4 Sheets-Sheet 2INVENTOR. MARVIN L. f/xcks Jan. 9, 1951 Filed Nov. 225, 1948 All]:

M. L. HICKS SHUTTLE ACTUATING MECHANISM 4 Sheets-Sheet 3 & a

INVENTOR.

MAI? W L. HICKS ym/vgzf;

Jan. 9, 1951 M. HICKS SHUTTLE ACTUATING MECHANISM Filed Nov. 23, 1948 4Sheets-Sheet 4 MAR VIN L. Hicks Patented Jan. 9, 1951 SHUTTLE ACTUATINGMECHANISM Marvin L. Hicks, Greenville, S. 0., assignor of one-half toRufus N. Ward, Greenville, S. C.

Application November 23, 1948, Serial No. 61,649

15 Claims. I

The present invention relates to loom assemblies, and more particularlyhas reference to a control arrangement for motions of the picker sticksemployed with the loom.

Heretofore, the movement of the picker stick to strike the shuttle whenit is boxed has been controlled through a camming mechanism generallyassociated with the cam shaft of the loom. This type of control is verycomplex structurally and because of the relatively large number ofworking parts that are required to impart movement to the picker stick,the devices often require adjustment of the parts or replacement orrepair of the damaged members. This is not only a time-consuming processbut is also quite expensive.

Accordingly, an important object of my invention is to provide a controlfor a picker stick which includes relatively few Working parts, which ispositive and efiicient in operation and which can be readily installedon all types of looms currently employed in the field, with a fewalterations according to make and type model of loom.

Another object of my invention is to provide a control for the pickerstick wherein either pneumatic means or liquid means is provided to movethe picker stick to drive the shuttle across the loom from box to box.

Yet a further object of my invention is to pro vide a control for thepicker stick wherein the picker stick is carried by a shaft disposed inapproximately parallel relation to the lay, the picker stick beingfixedly secured to the shaft at approximately right angles to the lay,the shaft being so mounted as to have reciprocating movement, thereciprocating movement being imparted to the shaft by either pneumatic,liquid or fluid means.

And yet another object of my invention is to provide a pneumatic controland fluid control for the picker stick of a loom wherein a novel valvestructure is associated with pneumatic and fluid control for operatingthe control.

An additional object of the invention is to provide a locking assemblyfor the picker shaft, which assembly will prevent reciprocation of theshaft until a predetermined pressure exists in either fluid or pneumaticcontrol means.

To accomplish the above and other objects, the invention broadlycomprises locating a picker stick adjacent each end of a picker shaftwhich is mounted for reciprocating movement with respect to the lay andoscillating movements of the swords of the loom in approximatelyparallel relation to the lay at a point below the lay. A pair ofcylinders are carried by a frame between swords in spaced parallelrelation to the picker shaft, the piston or connection rod beingdisposed at approximately the mid point of the lay. The piston in eachcylinder located off center side is carried by a common piston rod, andan arm secured to the central point of the picker shaft is suitablyconnected to the piston rods. A control valve is provided for eachpiston which alternate the pressure to cylinder and each valvecommunicates with a source of constant pressure which, in turn, isconnected to a suitable source of supply and a means of discharge forthe used pressure.

An equalizing unit which includes a cylinder in communication with asource of constant pressure is operatively connected through its pistonrod with a pair of cylinders of the same capacity, one of the lattercylinders being coupled to one of the control cylinders, whereas theother cylinder is connected to the opposite control cylinder. A brakedevice is carried by the piston and normally engages the picker shaft topresent reciprocatory movement from being imparted to the shaft, unlessthere is sulflcient pressure in cylinder to drive shuttle across theloom.

Each of the valves associated with the control cylinders is providedwith an arm which is adapted to be moved to change the position of thecon trol to admit pressure into the cylinder to move the piston whilethe other cylinder is exhausted and, as a consequence, the picker shaftis moved in the same direction when the lay is in the back centerposition.

When the shuttle is boxed and the arm moves the control valve to admitpressure into the control cylinder, that pressure will also be divertedinto the cylinder of the equalizing unit associated therewith and untilthe pressure equals that of the constant pressure cylinder, the brakedevice will prevent reciprocation of the picker shaft, and when thispressure is attained, the longitudinal movement of the picker shaft willlikewise move the picker stick, thereby striking the shuttle and driveit across the loom.

To adapt the above control for use with fluid or liquid, 2. pressuretank is connected with the inlet port of each control valve, and anotherline communicates with a pump driven by an electric motor which may beactuated by a pressure responsive switch. A vacuum tank is also incommunication with the pump and a conduit extends from the dischargeport of each control valve to the tank.

In lieu of a mechanical operator for the con trol valve, this valve maybe actuated by electrical means. A circuit may be completed and theshuttle is boxed and the lay is in back center to actuate a solenoidassociated with the valve to rotate the valve plug the desired distance.

Figure 1 is an elevational View of one form of loom equipped with mycontrol arrangement for motions of the picker sticks.

Figure 2 is a view in side elevation, partly broken away, showing thecylinders and their related elements for imparting reciprocatorymovement to the picker shaft.

Figure 3 is a sectional view taken along the line 3-3 of Figure 2,looking in the direction of the arrows.

Figure is a plan view, partly broken away and partly in section, of thecylinders, together with the means for actuating the control valve forthe cylinders.

Figure 5 is a sectional view taken along the line 55 of Figure 4, butbeing on a somewhat enlarged scale.

Figure 6 is a sectional view taken along the line 65 of Figure 5,looking in the direction of the arrows.

Figure 7 is a sectional view taken along the line i-l of Figure 2,looking in the direction of the arrows.

Figure 8 is a view taken along the line 88 of Figure 1, looking in thedirection of the arrows, but being on a somewhat enlarged scale.

Figure 9 is a diagrammatic representation of a modification wherein afluid is employed to control motions of the picker sticks.

In Figure 1, I have shown a loom including frame iii, a rocker shaft lljournaled in the frame, and to which swords l2 for oscillating lay itare attached. A power shaft (not shown) is operatively connected to bothof the swords through suitable linkage to rock the swords about theshaft H, and as this structure is well known in the art, it is notthought necessary that it be illustrated.

A gear M provided on the power shaft meshes set or warp threads andalternately pull down adjacent ones so that movement of shuttle 26across the loom will insert the filling thread at each change orposition of the warp threads, and the reed will pack together theinserted filling threads,

Figure 1 it will be seen that the shuttle is boxed at the left hand sideof the loom adjacent picker stick designated generally 21. The pickerstick 23' includes a standard 28, preferably of wood, which is securedin a socket 29 formed at the outer end of a picker shaft 3!! mounted inreciprocating bearings 55! secured to a support or panel ill/i betweenthe swords l2 so as to extend out and under the lay. The picker shaft ismounted below and in the center of and in substantially parallelrelationship to the lay it, as illustrated clearly in Figure 2. Asupport or bracket 32 is bolted to each sword, as shown at 33, and is ofarcuate configuration, as shown in Figure 8. The support is formed witha plurality of longitudinally extending grooves 34 in which are mounteda plurality of bali bearings 35 upon which the outer periphery of theshaft 38 is seated. The sides of the support 32 extend above the centerof the shaft, thereby preventing appreciable lateral movement of theshaft, which has always been a troublesome problem in looms, and, inaddition, the support will prevent bending of the shaft downwardlyduring operation.

The standard 28 of the picker shaft projects through slot 36 in the layand it can be seen that with the present invention, it is possible toemploy a picker stick of considerably less height than those currentlyemployed wherein the movement of the stick is usually imparted bymechanical means associated with the cam shaft of the loom.

In order to impart the necessary longitudinal movement to the pickershaft, it will be noted that I provide a pair of opposed cylinders 38,each of which is attached rigidly to the panel at a point above thepicker shaft 30, as indicated at 39. A piston M3 is movable in eachcylinder and each piston is carried by a piston rod 4!, the piston rodbeing disposed at approximately the mid point of the lay It. The inneror free end of each rod is reduced and threaded, as at MB for engagingcomplemental threads in an arm 42. When the rods have been threaded intothe arm, screws 33 are tightened to secure the parts together. The lowerend of the arm carries a split sleeve 34 which is attached to the pickershaft 35 at the central point of the picker shaft and locked thereto byscrew 46. Manifestly, if pressure is admitted into the left handcylinder 38 (Figures 2 and 4), the piston therein will force the arm 52and consequently the picker shaft 30 toward the right, whereby thepicker stick 2'! will strike the shuttle to drive it across the loom.

To control the flow of pressure in the cylinders, I provide a valveassembly #55 associated with the head of each cylinder. As indicated inFigures l and 6, the valve comprises a body 46 which is flanged, asshown at M, and the cylinder is attached to the flange by bolts or thelike $8. The valve body tie is provided with a substantially centrallylocated recess or bore 59 having inclined walls 59 in which is located aplug 5!, the walls of which have a taper corresponding to that of theWalls 50. A pin 52 is suitably attached to the bottom wall of the plugBI and extends downwardly therefrom through an opening in the valve body45, and the outer end of the pin is threaded, as shown at 53, to receivelock nuts ed. A washer 55 is located adjacent the inner lock nut and aspring 56 surrounds the pin between the washer and the base or bottomwall of the body it. By drawing up the nuts 54, it is clear that the pin52 will be moved downwardly, thereby moving the plug 5| downwardly to aposition which will prevent any leakage in the valve assembly.

The valve body is provided with an inlet port 51, a discharge port 58,and ports 53 til, which latter ports are in communication with theinterior of the cylinder 38. Ihe plug El a port or channel 6! extendingtherethrough and the ports 5?, 58, 59 and Eli are located 99 degreesapart with respect to the bore 39, as is perhaps best shown in Figure 6.The location of these ports is very important, in that it permits thesuccessful operation of the control assembly.

A shaft 62 is attached to the top of the plug 5i and is supported byarms 63 attached tothe valve body i5. An annular member 54 is detachablyconnected to the upper end of the shaft 62, as shown at 65, and supportsoutwardly extending arms 55, there being four such arms, each arm beingdiametrically opposed, or, in other words, the arms being carried by theannular member at intervals of 6 degrees.

To insure that the port 6! will be in proper alinement with the ports inthe valve body, it will be noted that the body is provided with achannel 6?, at the outer end of which is seated a spring-pressed ball68. The plug iii is formed with a hemispherical depression 59 so thatwhen the plug has been turned to the point where the desired ports arein alinement, the ball 68 will be forced into the depression, therebylocking the plug with respect to the valve body. ihe inlet port isconnected to a source of constant pressure it mounted on a beam iicarried by the frame ill at a point adjacent the lower end of the frame,by means of a conduit if. The source of pressure, namely a tank or thelike, may be connected to a central supply tank (not shown) by a conduitl3, and a pressure regulator valve MB is interposed in the conduit tokeep the pressure at a constan desired level for operation. Theadjustment of the valve enables the tank to be kept at a predeterminedpoundage pressure necessary for the power to drive the shuttle acrossthe loom. The discharge outlet 58 may be provided with a hose or otherconduit it which terminates near the floor for eliminating water, oil,etc.

To actuate or turn the valve plug 5!, the frame it supports a beam 55upon which is mounted a finger i5, there being one finger for eachvalve. The finger it is downwardly curved, as a' ll, shown in Fig. 3 andeach finger 75 is adapted, when the lay is in the back center position,to engage one of the arms to and thereby move the plugs iii a quarterturn. To explain more clearly the operation, it is assumed that theshuttle 26 is at the left hand side of the loom, and as the lay moves tothe back center position, the finger it will engage one of the armsthereby turning the plug E-i until the port therein communiwith port 5?,and in this position (Figure 6), the port of will also communicate withthe port whereby the cylinder will be in communication with the pressurefrom the tank 'id. Simultaneoi the valve associated with the oppositecylinder will be moved so that that cylinder will be in communicationwith the discharge conduit through the ports 5i), iii and the dischargeport 58. Manifestly, the piston ill wil be moved toward the right,thereby imparting a similar movement to the picker shaft 3i! so that thepicker stick will drive the shuttle 25 across the With repeated movementof valve con rol, the cycle of operation will continued during theoperation of the loom.

To insure that there is suficient pressure in the cylinder to drive theshuttle across the loom, I provide equalizing device designatedgenerally 3i]. The equalizing device cornprises a cylinder 8i having apiston 32 movable therein. Spaced from the cylinder iii are a pair ofcylinders 85., and piston 85 of each cylinder has a rod 85 attached to across-pieee El which, in is connected to piston rod iii. of the piston82. Each of the cylinders ti, 63 and is of equal capacity, and thecylinder iii is tapped into the pressure port 5? of the right of theleft hand valve assembly 3-5 by a conduit 89 and into the equivalentport of the right hand valve assembly 45 by means of the conduit 89'.fhe cylinder 83 is connected with the head of the left cylinder 38 by aconduit 93 (Figure 6), whereas the cylinder 8 communicates with the headof the other cylinder 33 through line 9!. A spring 92 is interposedbetween the cross-piece 87 and the casing of the cylinders 83 and 8 4,and the purpose thereof will be later more fully described.

An arcuate member 93 is detachably connected to the shaft 88 andsupports a brake shoe 9% which is adapted to engage the picker shaft 35and in the engaged position serves to prevent iongitudinal movement ofthe shaft. Consequently, it can be seen that since the piston 84 is incom munication with the source of constant pressure at the pressureports of the control valve, the brake shoe will be held in engagementwith the shaft until the pressure admitted into the cylinder 38 is equalto the pressure in the valve port 5?. When this pressure is attained,for example, in the left cylinder 38, the pressure in the cylinder 83will equal that in the cylinder 8|, whereupon the spring t2 will forcethe piston rod 8% toward the left (Figure 7). In other words, when equalpressure is on both cylinders, the common connecting rod is free and thespring urges the rod and piston into the single cylinder by thismovement, thus moving the brake shoe 94 away from the shaft 3b to enablethe shaft to reciprocate so that the picker stick may drive the shuttleacross the loom.

The equalizer assembly as is mounted to the panel 30A by a stand orbracket 95, and while for illustration purposes it is shown adjacent oneof the swords, I have ascertained that an excellent location is to theleft of the loom center near one of the members supporting a bearing.While the cylinders Si, 83 and 84 are shown disposed horizontally, it isapparent that these units may be located vertically with respect to thepicker shaft, and this change can be easily accomplished by one skilledin the field.

In Figure 9, I have illustrated another form of control wherein a fluidor liquid is utilized to actuate the motion of the picker sticlm. Sincethe cylinders and their related elements are similar to those shown inFigure 1, the same reference characters will be applied to these parts.

A pressure tank 568 adapted to contain threefourths fluid and one-fourthair pressure is suitably suported by a beam or the like extendingbetween the loom frame ends. A pair of lines or conduits Iiil and Hillextend from the bottom of the tank use to the inlet port 5? of the valveassemblies 45 at the left hand and right hand. The tank IE0 is alsoconnected by means of a conduit I02 to a pump lot which is driven byelectric motor ltd controlled through a pressure operated switch m5interposed in the line [82.

A vacuum tank Hit of lesser capacity than the tank Hill is alsosupported by a member carried by the loom frame ends and the capacity ofthis tank is three-fourths air space and one-fourth fluid. A line Iii!extends from the tank 36 to the pump it, and a one-way valve m8 isinterposed between the tank and the pump. A similar valve I 09 is alsoprovided in the line Hi2 between the tank I on and the pump I63.

A pair of conduits Iii? extend from the tank I96 to the outlet ordischarge port 58 of each 01' the valves 45.

It is clear that the pressure in the tank I01! will force the fluidthrough the conduits Ilil into the valve port 51 of the body d5, therebymoving the piston in the cylinder to reciprocate the picker shaft andsimultaneously, of course, fluid will be exhausted from the oppositecylinder through the line iii] to the vacuum tank [65. In other words,the tank lilil is in the nature of a hydraulic ram in that the airpressure in the tank will force the fluid through the conduits it! andHit, it being understood that there will always be fluid in the tank I08and in the vacuum tank H36 from which the fluid is removed throughsuction action.

The pressure operated switch I515 for operating the motor will keep thepressure constant and the switch may be adjusted to increase or diminishthe pressure. Hence, it can be seen that it is a very simple operationto convert the control as illustrated in Figure l to a fluid assembly bythe inclusion of the vacuum tank, the pump, the motor and the pressureswitch.

It is also advantageous to provide a means for lubricating the pistolsin the cylinders 38 and this may be done by locating a lubricant supplytank above the cylinders and carried by the lay. An oil line may leadfrom each end of the tank into the cylinders.

To enable the picker shaft se to be easily assembled or disassembled,this shaft may be made in three sections, the individual sections beingconnected together by means of sleeves or the like. Additionally, theshaft 35] is provided with a pair of collars H2 having set screws H3 sothat the length of reciprocating movement of the shaft may be adjusted.These collars further function as stops against resilient pads orbumpers id carried by the bearings 3i disposed below the base of thecylinders. In other words, this assembly will aid in absorbing the shockat the end of the throwing motion of the picker shaft and eliminate thesound of metal hitting metal. The same results may be accomplished byproviding a resilient bumper on the connecting rod ti adjacent eachcylinder 38.

It is, of course, to be understood that each picker stick 2! is providedwith a check strap and the check strap arm may be attached at its endsto the lay and support 32, rspectively. By being connected to thesupport, the check strap arm acts as a stabilizer for the support as itmoves with the motion of the lay. In certain types of looms, the frameis too high to accommodate the check strap above the support 32 and inthis situation the picker shaft may be located above the cylindersadjacent the bottom of the lay. This would necessitate the longitudinalslotting of the support 32 to permit the picker stick to extend slow thesupport to enable the check strap to be associated therewith.

Since the finger i6 is fixed to the beam carried by the frame, the laymovement functions as a supply of force to move the arms and if movementof the lay is arrested, the picker motion does not operate. Each arm 65may be pivotally mounted to the annular member G l and spring meansassociated therewith will hold the arm extended and yet enable the armto move inwardly relative to the member 6 5.

I claim:

1. In a control assembly for imparting movement the picker sticks of aloom having a frame, a lay swords for oscillating the lay mounted forrocking movement on the frame, a picker shaft disposed below the lay andmounted for reciprocating movement relative to the lay, a picker sticksupported at each end of the picker shaft and extending through a slotin the lay, pressure operated means supported by the swords, aconnection between the pressure operated means and the picker shaft,means carried by the frame adapted to actuate the pressure operatedmeans when the lay is in back center position to move the picker shaftso that the picker stick will drive the shuttle across the loom and abracket secured to each sword and extending outwardly therefrom tosupport the outer end of the picker shaft throughout its full stroke ofmovement.

2. A control assembly as claimed in claim 1 wherein the pressureoperated means is supported by a member extending bet-ween the swords.

3. A control assembly as claimed in claim 1 wherein the pressureoperated means is supported above and parallel to the picker shaft.

4. A control assembly as claimed in claim 1 wherein the picker shaft ismounted below and equidistant from the front and rear edges of the lay.

5. In a control assembly for imparting movement to the picker sticks ofa loom having a frame, a lay and swords for oscillatin the lay mountedfor rocking movement on the frame, a picker shaft disposed below the layand mounted for reciprocating movement relative to the lay, a pickerstick supported at each end of the picker shaft and extendin through aslot in the lay, a support attached to the swords, a pair of opposedcylinders supported by the support, a piston in each cylinder, a rodconnecting said pistons, an arm secured at one end to the connecting rodand at the other end to the picker shaft, a valve means associated witheach cylinder, a source of constant pressure, a connection between thepressure source and each valve means, actuating means for the valvemeans, and a pair of fingers on the frame adapted to move the actuatingmeans when the lay is in the back center position so that when one valveis moved to admit pressure to its cylinder, the other valve moves toplace its cylinder in communication with the atmosphere whereby thepiston in the cylinder under pressure will reciprocate the picker shaftthus enabling the picker stick to drive the shuttle across the loom.

6. A control assembly as claimed in claim 5 wherein the picker shaft ismounted below and equidistant from the front and rear edges of the lay.

7. A control assembly as claimed in claim 5 and braking means to preventreciprocation of the picker shaft until the pressure in the cylinder issufficient to drive the shuttle across the lay.

8. A control assembly as claimed in claim 5 wherein the valve meansincludes a body having a port in communication with the pressure source,a, port in communication with the atmos phere, at least one port incommunication with the cylinder, a plug rotatably mounted within thebody having a port extending radially therethrough, and diametricallyopposed arms carried by the plug so that when the lay is in the backcenter position the finger on the frame will contact one of the arms tomove the plug 90 degrees with respect to the body, thereb alining thebore in the plug with the desired bore in the body.

9. A control assembly as claimed in claim 5 wherein the connecting rodbetween the pistons is disposed at the longitudinal center of the lay.

A control assern ly as claimed in claim 5 wherein the arm is attached tothe center of the picker shaft.

11. A control assembly as claimed in claim 5 wherein a bracket issecured to each sword and extends outwardly therefrom for supporting theouter end of the picker shaft.

12. In a control assembly for imparting movement to the picker sticks ofa loom having a frame, a lay and swords for oscillating the lay mountedfor rocking movement on the frame, a picker shaft located below andsupported for reciprocating movement with respect to the lay, a pickerstick carried at each end of the picker shaft and extending through aslot in the lay, a beam attached to the swords, a pair of opposedcylinders supported by the beam, a piston in each cylinder, a rodconnecting said pistons, an arm secured at one end to said connectingrod and at the opposite end to the picker shaft, a valve meansassociated with each cylinder, a source of fluid, a connection betweenthe source of fluid and each valve means, a vacuum tank, connectionsbetween said vacuum tank and each of said valve means, pumping means, aconduit from said pumping means to said fluid source, a con duit fromsaid vacuum tank to said pumping means, actuating means for said valvemeans, and a pair of spaced fingers on the frame adapted to move theactuating means when the lay is in the back center position whereby onevalve means is moved to admit fluid into its cylinder while the othervalve means moves to place its cylinder in communication with the vacuumtank whereby the piston under fluid pressure will move the picker shaftso that the picker stick will drive the shuttle across the loom.

13. In a control assembly for imparting movement to the picker sticks ofa loom having a frame, lay and swords for oscillating the lay mountedfor rocking movement on the frame, a picker shaft disposed below the layand mounted for reciprocating movement relative to the lay, a pickerstick supported at each end of the picker shaft and extending through aslot in the lay, a support extending between and secured to the swordsbeneath the lay, pressure operated means supported by the support, aconnection between the pressure operated means and the picker shaft,means carried by the frame adapted to actuate the pressure operatedmeans when the lay is in back center position to move the picker shaftso that the picker stick will drive the shuttle across the loom, andmeans cooperating with the picker shaft to prevent reciprocation of thepicker shaft until the pressure in the pressure operated means issufficient to drive the shuttle across the lay.

14. In a control assembly for imparting movement to the picker sticks ofa loom having a frame, a lay and swords for oscillating the lay mountedfor rocking movement on the frame,

a picker shaft disposed below the lay and mounted for reciprocatingmovement relative to the lay, a picker stick supported at each end ofthe picker shaft and extending through a slot in the lay,'a supportattached to the swords, a pair of opposed cylinders supported by thesupport, a piston in each cylinder, a rod connecting said pistons, anarm secured at one end to the connecting rod and at the other end to thepicker shaft, a valve means associated with each cylinder, a source ofconstant pressure, a connection between the pressure source and eachvalve means, actuating means for the valve means, and means on the frameadapted to move the actuating means when the lay is in the back centerposition so that when one valve is moved to admit pressure to itscylinder, the other valve moves to place its cylinder in communicationwith the atmosphere whereby the piston in the cylinder under pressurewill reciprocate the picker shaft thus enabling the picker stick todrive the shuttle across the loom.

15. In a control assembly as claimed in claim 14 wherein means isprovided to prevent reciprocation of the picker stick until the pressurein one of the opposed cylinders is sufficient to drive the shuttleacross the lay, said means including a cylinder in communication withthe source of constant pressure, two cylinders supported op-' positesaid first named cylinder, the said cylinders being of equal capacity, apiston in each of said cylinders, a piston rod for the said pistons,means connecting the piston rods, means connecting one of the oppositelydisposed cylinders with one of the cylinders on the support secured tothe swords, means connecting the other of the said oppositely disposedcylinders with the other of the cylinders on the support between theswords, a braking member carried by the means connecting the piston rodsfor engaging the picker shaft, and spring means tending to urge thebraking member away from the picker shaft.

MARVIN L. HICKS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 781,632 Cobb et al Feb. I, 1905795,731 Patterson July 25, 1905 1,186,680 Potstada June 13, 19161,847,584 Winters Mar. 1, 1932 2,355,540 Layton et al Aug. 8, 1944

